Typically a micro gyroscope contains a set of pairing circumferential comb-shaped microstructures with plurality of fine fingers spaced apart but interwoven to form one or several capacitors sensing the rotation and angular acceleration of the carrying substrate on which the set of paring circumferential comb-shaped microstructures are mechanically suspended.
Such a micro gyroscope is commonly processed through a so-called bulk MEMS fabrication process, which employs deep reactive ion etch (DRIE) through the thickness of a silicon wafer, typically hundreds of micro meter thick. The fundamentals of such bulk MEMS fabrication process limit the process tolerance of lateral dimensions and therefore, the sensing accuracy with the two circumferential comb-shaped microstructures in pair as sensing capacitors. Furthermore, such a micro gyroscopic device is very difficult to be miniaturized like silicon-based microelectronic devices and also, incurs bottomline fabrication costs because the fabrication needs special bulk MEMS fabrication device.